JPS6149154A - Control device for automobile - Google Patents

Abstract

PURPOSE:To enhance utilization efficiency of hardware resources in a computer and improve its processing speed, by providing an abnormality discriminating means which controls the action of an output switching means selecting a control output signal from the two microcomputers. CONSTITUTION:The first microcomputer 11 distributively loads a main task formally executing one divided control item EGI (fuel injection quantity control) and an ADV (ignition timing control) and subtask informally executing the other divided control item ISC (idle speed control) and an ETC (the other). The second microcomputer 12 distributively loads a subtask informally executing one divided control item (EGI, ADV) and a main task formlly executing the other divided control item (ISC, ETC). An abnormality discriminating circuit 14 controls the action of an output switching circuit 13. In this way, a control device, enhancing utilization efficiency of hardware resources in the computer, improves its processing speed.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a control device for an automobile, and in particular uses a microcomputer to process multiple types of control items, and uses two microcomputers to provide backup in the event of a failure of one of the control devices. Concerning those who do.

(Prior art) -C. Particularly high reliability is required for automobile control devices, as their failure is highly likely to lead to an accident.For this reason, automobile control devices using microcomputers are required. There is a system that is equipped with two microcomputers, a main microcomputer and a submicrocomputer, so that in the unlikely event that the main microcomputer malfunctions, the submicrocomputer ensures the minimum control operation. .

FIG. 2 shows an example of a conventional control device for an automobile of this type.

The automobile control device shown in the figure includes a main microcomputer (main CPU) 1. Secondary microcomputer (secondary cpU)
)2. Output switching circuit 3. Abnormality determination circuit 4. input boat 5
．． It is composed of crystal oscillators 6, 7, etc. for generating clock signals.

The main microcomputer 1 and the sub microcomputer 2 each have ECI (fuel injection amount control).

It has the function of processing multiple types of control items such as ADV (ignition timing side 4a[I), ISC (idle rotation speed control), and ETC (other). in this case,
The main microcomputer 1 executes regular tasks for all of the plurality of control items described above, but the sub microcomputer 2 executes regular tasks for each of the plurality of control items, while the sub microcomputer 2 performs simple tasks to maintain the minimum operation of the controlled system 8 for each of the control items. It is configured to perform the task specified.

During normal operation, only the main microcomputer 1 operates.

Then, the main control output signal EGII is properly processed by the main microcomputer 1.

ADVl, l5C1, and ETCI are sent to the controlled system 8 via the output switching circuit 3. At this time, the sub microcomputer 2 is disconnected from the controlled system 8 and is in a dormant state.

Here, when an abnormality occurs in the operation of the main microcomputer 1, the main control output signals EGII, ADVI, and I5CI from the main microcomputer 1 are output.

ETCl is disconnected from the controlled system 8. Instead, a simplified sub-control output signal EGI2. ADV2. lSC2 and ETC2 are now sent to the controlled system 8 via the output switching circuit 3.

As a result, even if the main microcomputer 1 fails,
The minimum necessary operation is ensured.

The abnormality determination circuit 4 determines whether or not an abnormality has occurred in the operation of the main microcomputer 1 by monitoring the cycle of the program run signal S1 that the main microcomputer 1 issues every loop execution cycle of the program. If an abnormality occurs, a start signal 11 is sent to the sub-microcomputer 2. Furthermore, the switching control signal C1 is sent to the output switching circuit 3 to disconnect the main microcomputer 1 from the controlled system 8 and connect the sub microcomputer 2 to the controlled system 8. Thereby, the sub microcomputer 2 can control the actuated system 8 instead of the main microcomputer 1.

In addition, EGII and ECI2 output the main and sub control output signals that control the amount of fuel injected by the fuel injector to the ADV.
I and ADV2 are the main and sub control output signals that control the ignition timing, rsci and l502 are the main and sub control output signals that control the idle speed by the idle speed control valve, and ETCI and ETC2 are for other operations. The main and sub control output signals to be controlled are shown respectively.

<Problems to be Solved by the Invention> However, in the above-mentioned automobile control device, it is necessary to provide the sub-microcomputer 2 which is in a dormant state and is not used during normal operation, which increases the cost and requires less hardware. The main microcomputer 1 has the problem of inefficient use of hardware resources, and since it has to process all control items normally, the processing load is heavy (this causes its hardware to There was a problem in that the hardware and software configuration became a major loss.

The present invention solves the above problems, and includes:
The purpose of this is to have a relatively small-scale and low-cost configuration that has a backup function in case a malfunction occurs in the microcomputer's operation, increases the efficiency of using hardware resources, and improves processing efficiency. The object of the present invention is to provide a control device for an automobile that enables improvement in performance, particularly processing speed.

Means for Solving the Problems> In order to achieve the above object, the present invention provides an automobile control device in which a microcomputer processes a plurality of types of control items. Second
It is equipped with two microcomputers, and both microcomputers are almost equally responsible for regular main processing during normal operation and simplified sub-processing when an abnormality occurs, and each microcomputer has its own main processing. All control items can be handled independently by processing and sub-processing, and the first. Output switching means that selects a control output signal output from the second microcomputer for each control item and sends it to the controlled system;
1st. The abnormal operation of the second microcomputer is separately determined, and if the operations of both the first and second microcomputers are normal, the main control output signal is obtained by both microcomputers executing their respective main tasks. If an abnormality occurs in the operation of one of the microcomputers, the control output signal from the microcomputer in which the abnormality has occurred is prohibited, and The operation of the output switching means is controlled so that the microcomputer that is not experiencing an abnormality sends the main control output signal and the sub-control output signal obtained by executing the main task and the sub-task, respectively, to the controlled system. The present invention also includes an abnormality determination means for detecting an abnormality.

Effect> With the above configuration, the first effect is achieved. The processing load on each of the second two microcomputers is reduced, and by operating both microcomputers in parallel during normal operation, hardware resources can be used effectively and processing speed can be significantly improved. will be achieved.

<Embodiments> Hereinafter, preferred embodiments of the present invention will be described based on the drawings.

FIG. 1 shows an embodiment of an automobile control device according to the present invention.

The automobile control device shown in the figure uses a microcomputer to control multiple types of control items (EGI, ADV, ISO,
ETC), and first, the first. Second two microcomputers 1
1.12.

On the other hand, the above-mentioned plurality of control items (EGI, ADV.

ISC, ETC) is divided into two (EC; I and ADV, ISC and ETC) and each division control item (ECI).

A main task that performs regular control processing and a subtask that performs simplified control processing are prepared for each of ADV) and (ISO, ETC).

The first microcomputer 11 is assigned a main task of normally executing one divisional control item (EGI, ADV) and a subtask of simplifying and executing the other divisional control item (ISC, ETC). . In the second microcomputer 12, there are two divided control items (EGI, AD).
A sub-task that simply executes V) and a main task that normally executes the other divided control item (ISC, ETC) are divided.

Next, an output switching circuit 13 and an abnormality determination circuit 14 are provided. Note that 15 is an input port, 16 and 17 are crystal oscillators for generating clock signals, and 18 is a controlled system.

The output switching circuit 13 is the first. Control output signals output from the second microcomputer 11 and 12 for each control item are selected and sent to the controlled system 18.

Abnormality determination circuit 14, each microcomputer 11゜1
By monitoring the cycles of program run signals Sl and S2 issued by the microcomputers 2 for each loop execution cycle of the program, it is determined whether or not an abnormality has occurred in the operation of each of the microcomputers 11 and 12, respectively. Based on this determination result, the switching control signal C1 or c2 is
is sent to the output switching circuit 13 to disconnect the microcomputer 11 or 12 in which the abnormality has occurred from the controlled system 18. At the same time, it is configured to issue an operation stop command signal INI or IN2 to forcibly stop the operation of the microcomputer 11 or 12 in which the abnormality has occurred.

1st. If both the second microcomputers 11.12 are operating normally, both microcomputers 11.1
The main control output signals EC, 11, and ADVI are obtained by executing the main tasks of the main control signals EC, 11, and ADVI, respectively.

Only l5CI and ETCI are selected and the above controlled system 18
sent to. In this case, EGII and ADVI are from the first microcomputer 11 and 15CI.

ETCl is output from the second control unit 12, respectively. As a result, the controlled system 18 is properly controlled for all control items.

Here, if an abnormality occurs in the operation of either one of the microcomputers 11 (or 12), the control output signal EGI 1. ADVI (or l5
CI, ETCI) are prohibited, and the main control output signals l5CI, ETCI (or EGII, ADVl) obtained by the microcomputer 12 (or 11) that is not experiencing an abnormality executing the main task and sub-task, respectively. ) and sub-control output signal EGI2.
ADV2 (or lSC2, ETC2) is now sent to the controlled system 18. In other words, all control items (EGI) are controlled by the operation of only the microcomputer 12 (or 11) that is not experiencing an abnormality.

ADV, ISC, ETC) are controlled. In this case, half of all control items are simplified and processed by subtasks, but only the minimum operations required to maintain safety can be ensured.

As described above, the first step. Even if one of the second microcomputers fails, backup is performed by the remaining microcomputer without failure. Also, 1st. Since the second microcomputers can be configured identically to each other, it is easier to reduce costs through mass production compared to the case where two types of microcomputers with widely different specifications are used. Moreover, each microcomputer controls all control items (EGI, ADV, ISC, ETC).
Since half of the time can be processed by simplified sub-tasks,
All control items will now be processed normally. Furthermore, since both microcomputers are operated in parallel during normal operation, effective use of hardware resources and significant improvement in processing speed can be achieved.

<Effects of the Invention> As is clear from the above explanation, the automobile control device according to the present invention has a relatively small-scale and low-cost configuration, and is capable of providing a bank-up function when an abnormality occurs in the operation of the microcomputer. (iii) It is possible to improve the utilization efficiency of hardware resources, and increase processing capacity.
In particular, the effect of making it possible to improve processing speed can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of an automobile control device according to the present invention, and FIG. 2 is a block diagram showing an example of a conventional automobile control device. 11...First microcomputer 12...
Second microcomputer 13... Output switching circuit 14... Abnormality determination circuit 15... Input port 1
8...Controlled system EC;I 1. ADVl, l5C
I, ETCl...Main control output signal EGI2. A.D.
V2゜lSC2,ETC2...Sub-control output signal Patent applicant Japan Electronics Co., Ltd. Agent Patent attorney Tomiji Sasashima hj [Figure 1 Figure 2

Claims (1)

[Claims] A control device for an automobile that processes a plurality of types of control items using a microcomputer includes two microcomputers, a first and a second microcomputer, which are configured identically to each other, and divides the plurality of control items into two, each of which is divided into two. For each control item, a main task that performs regular control processing and a subtask that performs simplified control processing are prepared, and the main task that normally executes one split control item and the other split control item are simplified. The first microcomputer is responsible for the sub-task that simplifies and executes one divided control item, and the main task that normally executes the other divided control item. output switching means for selecting control output signals output from the first and second microcomputers for each control item and sending the selected control output signals to the controlled system; Malfunctions in the microcomputers are determined individually, and if both the first and second microcomputers are operating normally, only the main control output signal obtained by both microcomputers executing their respective main tasks is selected. If an abnormality occurs in the operation of one of the microcomputers, the control output signal from the microcomputer in which the abnormality has occurred is prohibited, and the control output signal is transmitted to the controlled system. abnormality determining means for controlling the operation of said output switching means so that said microcomputer sends a main control output signal and a sub-control output signal obtained by executing a main task and a sub-task to said controlled system; An automobile control device comprising: